Brain research
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Neuropathic pain is one of the major problems of patients with spinal cord injury (SCI), which remains refractory to treatment despite a variety of therapeutic approach. Multimodal neuroimaging could provide complementary information for brain mechanisms underlying neuropathic pain, which could be based on development of more effective treatment strategies. Ten patients suffering from chronic neuropathic pain after SCI and 10 healthy controls underwent FDG-PET, T1-anatomical MRI and diffusion tensor imaging. ⋯ These results indicated that white matter changes imply abnormal pain modulation in patients as well as motor impairment. Our study showed the functional and structural multimodal imaging modality commonly identified the possible abnormalities in the brain regions participating pain modulation in neuropathic pain. Multifaceted imaging studies in neuropathic pain could be useful elucidating precise mechanisms of persistent pain, and providing future directions for treatment.
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This study clarified the neural mechanisms underlying jaw movements in pharyngolaryngeal reflexes such as swallowing in rats. After retrograde tracer injections into the ventromedial division (Vmovm) of the trigeminal motor nucleus (Vmo) containing jaw-opening (JO) motoneurons or into the dorsolateral division (Vmodl) of Vmo containing jaw-closing (JC) motoneurons, JO and JC premotoneurons were labeled with an ipsilateral predominance in the medial and intermediate subnuclei of the rostrocaudal middle two-thirds of the nucleus of the solitary tract (Sol); JC premotoneurons were also in the lateral subnucleus of Sol. After anterograde tracer injections into the Sol, axons were labeled with an ipsilateral predominance in the Vmovm and Vmodl, prominently in the ipsilateral Vmovm. ⋯ Double labeling experiments demonstrated contacts between the afferent terminals and the JO and JC premotoneurons. The present study has for the first time revealed the differential distribution of JO and JC premotoneurons in the Sol and features of their projections from the Sol, as well as their connections with SLN and GpN-ct afferent inputs. The JO and JC premotoneurons in the Sol may play an important role in generation and organization of jaw movements in pharyngolaryngeal reflexes evoked by SLN and GpN-ct inputs, such as swallowing.
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Medical intervention for major depressive disorder (MDD) can be more appropriately focused through the identification and characterization of neurobiological markers that are specific to the disorder, and this study aims to examine the abnormality in the fractional amplitude of low-frequency fluctuation (fALFF) and the amplitude of low-frequency fluctuation (ALFF) in currently depressed and remitted female MDD patients and to correlate these fluctuations with clinical markers of MDD. Nineteen currently depressed female patients, 19 remitted female patients, as well as 19 age- and education-matched healthy females participated in the resting-state functional magnetic resonance imaging (fMRI) analysis. We compared the fALFF/ALFF maps among the three groups and investigated the correlation between clinical measurements and statistically significant differences in the fALFF/ALFF of various brain regions. ⋯ The ALFF of the right precuneus was found to be positively correlated with the number of depressive episodes and the fALFF of the right precuneus to be positively correlated with the disease duration in currently depressed MDD patients. An abnormal fALFF/ALFF in the right ventral median frontal gyrus was found only in currently depressed patients, suggesting that such an anomaly may play a critical role in depressive symptomatology and may be a therapeutic target for MDD. An abnormal fALFF/ALFF in the right putamen is a potential candidate as a trait-related marker of vulnerability to major depression.